Vertical shake apparatus for papermaking wire



ec. 22, 1970 R. c. CLARK 3,549,487

' VERTICAL SHAKE mun/mus FOR PAPERMAKING WIRE Filed Jan. 12, 1967 IN VENTOR.

United States Patent O 3,549,487 VERTICAL SHAKE APPARATUS FOR PAPERMAKING WIRE Raymond C. Clark, Orange, Conn., assignor to Huyck Corporation,Rensselaer, N.Y., a corporation of New York Filed Jan. 12, 1967, Ser.No. 608,782 Int. Cl. D21f 1/20 U.S. Cl. 162-356 4 Claims ABSTRACT OF THEDISCLOSURE Thi invention relates to means for improving the formation ofa continuous web in a papermaking machine, and more specifically, tomeans for imparting vertical shaking movement to the forming medium inthe forming section of a fourdrinier papermaking machine.

BACKGROUND OF THE INVENTION In the typical fourdrinier papermakingmachine, which may be used for the production of paper, board, pulp,asbestos sheet and/ or other continuous web-like structures, an aqueoussuspension of fibers (such as cellulose and/ or mineral), called thefurnish, is flowed onto a traveling forming medium. Typically, theforming medium is a woven, screen-like structure made from metal wireand/ or synthetic filaments. Various drainage or dewatering elements aredisposed beneath the forming medium, such as table rolls, suction boxes,and/or hydrofoils (stationary drainage elements like that shown in U.S.Pat. No. 2,928,465). As the forming medium travels over the drainageelements, water is removed from the furnish producing a continuous webwhich is self-supporting to some extent. The web is then transferredfrom the forming section to the press section and then the dryer sectionof the papermaking machine where additional operations on the webcompact the web and remove still more water therefrom.

In order to aid the formation of the web, whether it be paper, board,pulp or sheet, a horizontal mechanical shake may be imparted to asubstantial part of the structure by which the forming medium issupported, and, hence to the forming medium, by suitable mechanicalmeans. This motion induces a more nearly random orientation andinterweaving of the web fibers in the furnish, and produces a web havingimproved and more uniform strength in the cross-machine direction aswell as the machine direction. This oscillation or shaking of theforming medium also prevents premature formation of the bottom portionof the web, a phenomenon which reduces the rate of drainage from thefurnish and prevents random movement of the fibers therein.

However, as the speed of the papermaking machine increases it becomesincreasingly difiicult to produce an effective oscillation of thefurnish and/ or forming medium, one reason being that at the higheroperating speeds of the machine, the furnish spends only a very shortperiod of time on the forming medium. Since the frequency of oscillationof the forming medium is limited by design and/or practicalconsiderations, such as splashing of the furnish at the deckel straps,no effective oscillation of the furnish will occur at high speedoperation of the machine. Further, in order to produce effectiveoscillations of the ever-increasing widths of the ice forming medium,complex machinery is required resulting in a high operating cost. Assuch, means should be provided for producing an effective oscillation ofthe furnish and/or forming medium in order to improve the formation ofthe web.

Therefore, one object of the present invention is to provide means forimproving the formation of a continuous web in a papermaking machine.

Another object of the present invention is to provide means forimproving the random orientation of the fibers of a web formed on apapermaking machine.

Another object of the present invention is to provide means forincreasing the drainage from a web formed on a papermaking machine.

Still another object of the present invention is to provide means forproducing an effective shake of the forming medium in a fourdriniermachine.

Still further, an object of the present invention is to provide meansfor imparting a vertical shake to the forming medium in a fourdrinierpapermaking machine.

SUMMARY OF THE INVENTION In accordance with the principles of thepresent invention, one embodiment thereof comprises, in a papermakingmachine, rotatable means for producing a vertical shaking of the formingmedium. The rotatable means is disposed beneath the forming medium andarranged to be in contact with the underside thereof. The rotatablemeans comprises a cylindrical roll having at least a single projectionextending from the surface thereof which intermittently engages theunderside of the forming medium upon rotation of the roll, producing avertical movement or shaking of the forming medium.

BRIEF DESCRIPTION OF THE DRAWING Additional objects and advantages ofthe present invention together with a better understanding thereof maybe had by referring to the following detailed description of the presentinvention together with the accompanying drawings, in which:

FIG. 1 is a simplified view of the forming section of a fourdrinierpapermaking machine;

FIG. 2 is a fragmentary view of the rotatable means for improving theformation of the web in the machine shown in FIG. 1;

FIG. 3 is a detailed fragmentary view of the rotatable means shown inFIG. 2; and

FIG. 4 is a section view of an alternate construction for the rotatablemeans shown in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to FIG. 1 there isshown the forming section of a papermaking machine wherein a continuousweb of fibrous material is being formed on a moving forming medium.Specifically, there is shown an endless forming medium 3 (moving fromleft to right as shown in the drawing) on which an aqueous suspension offibers (such as cellulose and/ or mineral fibers) is flowed from aheadbox in order to form a continuous web 5 of material such a paper,board, pulp, asbestos sheet or the like. The forming medium 3 is mountedabout a breast roll 7 and a couch roll 9 and is generally a wovenendless belt of all metal composition, all synthetic composition such asshown in U.S. Pat. #2,903,021Holden et al., a combination of metal andsynthetic materials, or

Patented Dec. 22, 1970 3 other suitable material such as a sheet ofperforated metal or plastic.

After being deposited on the forming medium 3, the aqueous suspension,or furnish as it is commonly called, is dewatered in order to removemuch of the water content therefrom and to form a somewhatself-supporting web. Drainage or other suitable dewatering means aid inthe removal of the water. As such, table rolls 13, stationary foilelements 15, and/ or suction boxes 17 are disposed beneath the formingmedium and in contact with the underside thereof, the operation of eachof such devices being well known in the art.

As previously mentioned, in order to produce a Web having uniformstrength in both the machine and crossmachine directions, it isnecessary that the individual fibers of the web be thoroughlycriss-crossed and interwoven while the web is being formed. That is, thefibers must be oriented in a random array while the furnish is still ina somewhat aqueous condition and before substantial amounts of water areremoved therefrom. Rotatable means 19 are provided for imparting avertical movement or shaking motion to the forming medium 3 in order tothoroughly criss-cross and interweave the Web fibers while the furnishis sill in a somewhat aqueous condition. The rotatable means 19 aredisposed beneath the forming medium 3 and arranged so as to contact theunderside thereof.

It can be seen (FIG. 2) that the rotatable means 19 comprises agenerally cylindrical roll 21 having at least a single projection 23extending therefrom. Preferably, the roll 21 will have many projections23 extending therefrom with the projections 23 engaging the underside of'the forming medium 3. Upon rotation of the cylindrical roll 21, (eitherby independent drive means or by motion imparted to the roll throughfrictional engagement of it with the moving forming medium), a verticalmovement or shaking motion is imparted to the forming medium 3. Itshould be noted that the rotatable means 19 may be rotatably afiixed tothe frame (not shown) of the fourdinier machine in any suitable manner.As such afiixing means are well known in the prior art, no furtherexplanation thereof is deemed necessary.

While many or few projections 23 may extend from the roll 21, it shouldbe noted that for optimum spacing of the projections 23, they arearranged in parallel rows which extend across the roll 21, the spacingbetween rows being such that a straight edge resting on projections inadjacent rows would just be tangent to the roll surface.

In the operation of a papermaking machine incorporating such a roll,rotation of the roll 21 will cause the projections 23 on the roll toengage intermittently the underside of the moving forming medium 3 andthereby impart to the forming medium 3 a vertical displacement from theroll surface 21. Appropriate spacing of the projections 23 will providea predetermined amount of vertical movement or oscillation of theforming medium 3 and furnish thereon for a given roll speed, which, inturn, Will produce random orientation of the web fibers.

It should be noted that as the forming medium 3 is forced away from therotating roll surface, a slight vacuum is created which aids in thedewatering of the web 5. However, when the forming medium 3 is incontact with the surface of the roll, the roll acts as a common tableroll. As such, it may be desirable to provide existing table rolls withprojections 23 in order to achieve the beneficial results of the presentinvention.

In order to avoid marking of the formed web 5, it is preferred toutilize a plurality of these knobbed rolls in a papermaking machine. Asseen in FIG. 3, the projectionsmay comprise integral button-likeelements which may be formed integral with the roll such as by castingthe whole structure (roll and projections together) in a suitable mold;or, and referring now to FIG. 4, the button-like projections 23 maycomprise an insert 24 which is fitted within a corresponding hole oropening 25 in the cylindrical roll 21, each hole 25 being adapted toreceive and hold a single insert 24. In the latter instance, each insert24 includes a head portion 29 and a stern portion 31; the stem portion31 fitting within the receiving hole 25 and the head portion 29 beingadapted to engage the underside of the forming medium 3. The stemportion 31 may be held in the hole 25 either by frictional engagementwith the wall of the hole or by the use of a suitable adhesive or thelike.

Peferably, the head portion 29 of the insert 24 is generallysemispherical or at least arcuate in configuration. Similarly, theintegral button-like projections will also be of an arcuateconfiguration. However, it is not the intention of the present inventionto be limited to such a configuration as such configuration is given byway of exmaple only. It should be noted, however, that the configurationused should not be so sharp as to cause damage to the forming medium 3.

Since the roll 21 will be in contact with the moving forming medium 3,it is generally desirable that the roll 21 and projections 23 be of arugged, wear-resistane and durable construction. As such, they may beformed of stainless steel, hard rubber or any other suitable material.When the projections 23 are formed integral with the roll 21, they willin most instances be formed of the same material as the roll. However,when the roll 21 as shown in FIG. 4 is utilized, the inserts 24 may beeither of the same material as the roll or of a different material. Thatis, stainless steel projections could be used with a hard rubber roll ora stainless steel roll could be used with hard rubber projections. Notethat other materials could also be used and stainless steel and hardrubber are given by way of example only.

Again, it is not the intention of the present invention to be limited tothe use of a single insert 24 fitting within a corresponding hole 25,and a plurality of inserts 24 may be fitted with a correspondingplurality of holes 25.

Thus, it can be seen that even with the tendency to operate papermakingmachines at higher speeds, and to increase the width of such machines,it is still possible to produce an effective shaking of the depositedsuspension so that the web fibers will be randomly arrayed in the formedweb. Further, paper, paper-like sheets, board, pulp, asbestos sheet, andany other similar fibrous formation may be made in the previouslymentioned manner.

While I have shown and described only particular embodiments of thepresent invention, it will become obvious to those skilled in the artthat additional changes and modifications may be made without departingfrom the present invention in its broader aspect. Therefore, it is theintention of the appended claims to cover all such changes andmodifications as fall within the true spirit and scope of the presentinvention.

What I claim as new and novel and desire to secure by Letters Patent ofthe United States is:

1. In the forming section of a papermaking machine wherein a continuousweb of fibrous material is formed from an aqueous suspension depositedon a moving form ing medium; the improvement comprising rotatable meansdisposed beneath the forming medium and in engagement with the undersidethereof, said means having a multiplicity of knob-like projections onthe surface thereof for selectively imparting intermittent verticaldisplacement to said forming medium in those regions in contact withsaid projection.

2. Apparatus as described in claim 1 wherein said projections are of asubstantially arcuate configuration.

3. In the forming section of a fourdrinier machine adapted to produce acontinuous fibrous web; comprising a moving forming medium on which thecontinuous web is formed, the improvement comprising rotatable meansdsposed beneath said forming medium and in engagement with the undersidethereof, said means having at least one knob-like projection from thesurface thereof for selectively imparting vertical displacement to said5 6 forming medium the region of contact with said pro- FOREIGN PATENTSlectlons- 187,711 3/1906 Germany 162356 4. Apparatus as described inclaim 3 wherein said projections are substantially arcuate in shape.

S. LEON BASHORE, Primary Examiner References Cit d 5 F. FREI, AssistantExaminer UNITED STATES PATENTS US Cl 1,536,599 5/1925 Aldrich 162-356162-209 1,917,098 7/1933 Cofrin 162355X 2,092,798 9/1937 Charlton162-356 l0

